Calculate the open circuit voltage, Electrical Engineering

This question is designed to give you practice in manipulating circuit equations using j notation, and to demonstrate that techniques that you have already studied in the d.c. context can be applied equally successfully to the solution of steady-state a.c. problems.

485_Calculate the open-circuit voltage.png

The sketch (right) shows the approximate equivalent circuit of a real transformer (inside the dotted line) with its parameters referred to the primary side, and with a referred load resistance of 5 ω. Find

(a) the open-circuit voltage VL , and

(b) the voltage across the 5 ω 'referred' load, by the following three methods.

 Method 1: Direct approach. First find the open circuit voltage by simple 'potential divider' approach (but with complex impedances Z replacing the simple resistances we used under d.c. conditions). Then find the equivalent series impedance of the two parallel branches on the right, and again use the 'potential divider' idea to find VL. The calculations are lengthy, and you will probably find it best to use polar form for the multiplications and divisions.

Method 2: Thévenin. Find the Thévenin equivalent circuit for the transformer and 100 V supply. Then apply the load and use the potential divider approach.

Method 3: Nodal Analysis. Call the node at the top of j35 node a and that at the top of the 5 ω load node b, with the reference (zero) node at the bottom. Write down the nodal equations in terms of the complex impedances, and solve for Vb.

Calculate the % change in the output voltage when the load is applied (this is known, as the 'regulation'). What would you expect the regulation to be if the transformer were ideal?

Posted Date: 2/22/2013 2:56:06 AM | Location : United States







Related Discussions:- Calculate the open circuit voltage, Assignment Help, Ask Question on Calculate the open circuit voltage, Get Answer, Expert's Help, Calculate the open circuit voltage Discussions

Write discussion on Calculate the open circuit voltage
Your posts are moderated
Related Questions
Question: a) What is the main difference between a latch and a flip flop? b) Draw the logic diagram of an SR-latch using only NAND gates. c) A positive edge triggered

Q. Explain working of Inverting Summing Amplifier? The circuit of Figure is extended by adding other input points, as shown in Figure. Because of the virtual ground at terminal

Explain Open Loop Control Systems In an open-loop control system, the controller independently computes exact voltage or current required by the actuator to do the job and send

What is the size of ports in 8255? Port-A : 8-bits Port-CU : 4-bits Port-B : 8-bits Port-CL : 4-bits

AC Machines: We have learnt the fundamental concepts of the transformer, induction motors and special type fractional kilowatt (kW) machines. In the section of transformer you

Briefly explain single mode and multimode fibres The optical fibres were categorized within two according to the number of modes it passes as: • Single mode fibres • Multi mode


Electric circuits or networks are formed by interconnecting various devices, sources, and components. Although the effects of each element (such as heating effects, electric-?eld e

Control  Bus The control  bus comprises of various  single  lines that carry  various  control  signals for synchronizing  various devices  and performing different task. The m

Q. If the line of Problem 15.1.3 is made of copper whose resistivity ρ = 1.72×10 -8 ·m, determine the maximum length that can be used if losses are not to exceed 3 dB when f = 3